A companion in V1247 Ori supported by motion in the pattern of the spiral arm
Bibliographic record
Abstract
While nearly two dozen spiral arms have been detected from planet-forming disks in near-infrared scattered light, none of their substellar drivers has been confirmed. By observing spiral systems in at least two epochs spanning multiple years and measuring the motion of the spirals, we can distinguish what causes the spirals and locate the orbits of the driving planets if the spirals are triggered by them. Upon a recent validation of this approach using the comotion between a stellar companion and a spiral, we obtained a second-epoch observation for the spiral system in the disk of V1247 Ori in the H-band polarized scattered light using Very Large Telescope (VLT), SPHERE, and IRDIS. By combining our observations with archival IRDIS data, we established a 4.8 yr timeline to constrain the spiral motion of V1247 Ori. We obtained a pattern speed of 0°.40 ± 0°.10 yr−1 for the northeast spiral. This corresponds to an orbital period of 900 ± 220 yr, and the semimajor axis of the hidden planetary driver therefore is 118 ± 20 au for a 2.0 ± 0.1 M⊙ central star. The location agrees with the gap in ALMA dust-continuum observations, which provides joint support for the hypothesis that a companion drives the scattered-light spirals while carving a millimeter gap. With an angular separation of 0″.29 ± 0″.05, this hidden companion is an ideal target for JWST imaging.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".